Multiple position vacuum switch



1963 JO EMMETT JENNINGS 3,079,481

MULTIPLE POSITION VACUUM SWITCH Filed May 19, 1961 IN VENTOR v0 EMMETTJE/VMA/GS 3,67%481 MULTHLE POSITHON VACUUM SWITCH Jo Emmett Jennings,San Jose, Calif, assignor, by mesue assignments, to leanings RadioManufacturing Corporation, San Jose, Calif., a corporation of DelawareFiled May 19, 1961, Ser. No. 111,254 6 Claims. (Cl. 200-444) Myinvention relates to vacuum switches and particularly to single polemultiple position switches.

One of the objects of my invention is the provision of a multipleposition switch particularly suitable for radio frequency applications.

Another object is the provision of such a switch which is insulatedinternally and so may be grounded at its mounting flange to permit safemanual operation.

Another object is the provision of a vacuum switch mechanism employing abellows seal and operating with so little wear that many millions ofoperations may be expected during its normal life.

Still further objects include the provision of a small vacuumized singlepole multiple position switch having extremely high resistance tovoltage break down, thermal stress, and mechanical shock.

Other objects will appear in the following description of my invention,in which I do not limit myself to the showing made by said descriptionand drawings, since I may use variant forms of the invention Within thescope of the appended claims.

Referring to the drawings:

FIG. 1 is an elevation of my vacuum switch partly in vertical halfsection.

FIG. 2 is a horizontal sectional view taken in the plane indicated bythe line 2-2 of FIG. 1.

FIG. 3 is an end view taken in the direction indicated by the arrow 3 ofFIG. 1.

Broadly my multiple position switch comprises a dielectric bulb or shellhaving an open end closed hermetically by a metallic mounting end plateand internally arranged bellows to form a vacuumized envelope. Anoperating lever extending through an aperture in the end plate andsecured to the closed end of the bellows permits the bellows to beswayed from side to side in operating of the switch, the lever slidingand pivoting in the aperture.

A non-conducting extension of the opera-ting lever is rigidly fixed onthe closed end of the bellows; and engages the end of a metal contactrod, the other end of which engages a central lead hermetically mountedin the end of the bulb. The contact rod is in effect a flexibleextension of the central lead, and the parts are so arranged that thecontact rod is resiliently held between the central lead and thenon-conductor extension of the lever by atmospheric pressure in thebellows. A plurality of poles is evenly arranged in the shell around thecontact rod, each pole being sealed in the shell providing a lead forconnection on the outside of the shell. These poles mark the differentpositions to which the contact rod may be swung to energize thediflerent circuits controlled by the switch, six in the switchillustrated, but which may vary from one to eight or even more.

By manipulation of the operator lever, the contact rod may be swungsideways out of its normal axial alignment and into contact with aselected pole, so that an electrical circuit is completed through thecentral lead, the contact rod and the chosen pole, a firm engagement ofcontact surfaces being maintained by the resilient pressure of thebellows.

In greater detail my switch as it is illustrated in the drawings,comprises a glass bulb or shell 2, closed at the ottom by a coppersealing ring 3, and an end mount- 3,b79,48l Patented Feb. 25, 1%63 ingplate 4. Secured to the mounting plate and extending downwardlytherefrom is a cup-like housing 6 in the bottom of which is an apertureof a shape designed to provide retention seats 7 for the manualoperating lever 8, when it is swung laterally from its central positionduring operation of the switch.

The operator 8 extends upwardly through an aperture 9 in the end plate4. The aperture is bordered by a rounded edge bead or flange 11, closelyconfining the operator, but with sufficient clearance to permit alimited pivotal and axial motion within the flange as a fulcrum andhearing.

The upper end of the operator is rigidly secured to a head 12 whichhermetically closes the upper end of a bellows 13, the lower open end 14of which is brazed and hermetically sealed to the end plate 4 whilesurrounding the operator 8 and the flanged bearing 11.

Extending upwardly from the bellows head is a sapphire or othernon-conductor shaft 16 held in rigid alignment with the operator 8 andin effect constituting an extension thereof. An effective means forinsuring a rugged connection comprises a stiff post 17 fixed rigidly inthe head 12. A yoke 18 having apertured spring arms 19 is rigidly brazedto the post with the arms slightly deflected from parallelism, so thatwhen the arms are held parallel and the sapphire shaft is threadedthrough the apertures and seated against the head 12, release of theyoke arms clamps the shaft 16 as a rigid extension of the operator 8.Keeper rings 21 are optional.

Sealed in the top of the bulb and in axial alignment with the operatorlever and its extension 16, is a central lead 22, continuous on theoutside of the bulb in the terminal stud 23. Both the end of lead 22 andof sapphire shaft 16 are semi-spherical in shape so as to make smoothlyoperating universal joints with the cupped ends of a cylindricalpreferably molybdenum distributor or contact rod 24. The rod is of suchlength between the lead and the shaft as to force a partial collapse ofthe bellows, so that atmospheric pressure within the bellows acts with asteady resilient pressure against the distributor rod.

Spaced downwardly from the top on the side of the envelope and in aplane perpendicular to the axis thereof, are a plurality of rodshermetically sealed in the wall and providing on the outside of theenvelope a plurality of terminal leads 26 and on the inside a pluralityof evenly spaced poles 27 extending radially toward the axis of the bulbin which the distributor lies when the switch is open, and with endsevenly spaced therefrom. Each of the poles is sli htly concaved at itsfree end to make surface contact with the distributor rod when it isswung to one side or the other to engage a chosen pole and close thecircuit of which the pole is a part.

Resilient upward pressure exerted by the bellows is suffiient to holdthe operating lever 8-16 and the distributor rod 24 in axial alignmentwith the center lead 22 as shown in the drawing. When the lever 3 isswung laterally to a selected seat 7 on one side of the axis thedistributor rod 24 resiliently engages a pole 27 on the opposite side,the bellows adjustin vertically and laterally automatically to theslight change, and the operator lever sliding and tipping slightly inits pivotal bearing flange 11 in the end plate. Because all of therelative movements of engaged parts are so small, and the flexing of allportions of the bellows are so minute in extent, my structure mayconfidently be expected to last without failure through many millions ofoperative cycles.

I claim:

1. A vacuum switch comprising a vacuumized dielectric bulb closed at oneend with a mounting plate having an aperture therein, a bellows having aclosed end and an open end hermetically fixed on the mounting platearound the aperture, an operating lever pivotally and slidscream ablyarranged in the mounting plate aperture and rigidly connected on theinside of the bellows to the closed end thereof, a dielectric shaftextension of the operating lever rigidly connected to the opposite sideof the closed end ofthe bellows and in alignment with the operatinglever, a metal rod hermetically sealed in the bulb Wall in alignmentwith the longitudinal axis of the bulb to form a terminal stud outsideand a central lead inside the bulb, a plurality of metal rodshermetically sealed in the bulb side wall to form terminal leads on theoutside and evenly spaced poles on the inside of the bulb extendingtoward the longitudinal axis of the bulb, and a metal distributor rodconstituting an extension of the central lead interposed between andmovably engaging the free ends of the central lead and the dielectricshaft and selectively engageable with the poles.

2. A vacuum switch in accordance with claim 1 in which means areprovided for positioning the operating;

lever to seat the distributor rod against a selected pole.

3. A vacuum switch according to claim 1 in which the dielectric shaft isclamped in the free endsof a U-shape 4. A vacuum switch according toclaim 1 in which the dielectric shaft is clamped in the free ends of aU-shape spring yoke, the yoke being spaced from the closed end of thebellows and rigidly mounted on a post rigidly extending therefrom 5. Avacuum switch according to claim 1 in which the distributor rod forms aball-socket engagement with the central lead and with the dielectricshaft.

6. A' vacuum switch according to clairn l in which atrnospheric pressurein the bellows provides resiliently applied force to the distributor rodfrom the dielectric shaft to retain the distributor rod in its position.

References Cited inthe file of this patent UNITED-STATES PATENTS1,784,302 Millikan et al. Dec. 9, 1930 1,829,037 Bobroff Oct. 27,1931

2,982,836 Jennings May 2, 1961' 3,001,046 Racz et al.l Sept. 19, 1961FOREIGN PATENTS 638,489 France Feb. 21, 1928 Disclaimer 3,079,481.J 0Emmett J enne'ngs, San Jose, Calif. MULTIPLE POSITION VACU- UM SWITCH.Patent dated Feb. 26, 1963. Disclaimer filed Apr. 15, 1963, by theassignee, Jennings Radio Manufacturing Corpomtion, the inventorapproving. Hereby enters this disclaimer to all the claims of saidpatent.

[Ofiez'al Gazette June 4, 1.963.]

Disclaimer 3,079,481.J 0 Emmett Jennings, San Jose, Calif. MULTIPLEPOSITION VACU- U'M SWITCH. Patent da ted Feb. 26, 1963. Disclaimer filedApr. 15,

1963, by the assignee, Jennings Radio Manufacturing Oor'pomtion,

the inventor approving.

Hereby enters this disclaimer to all the claims of said patent.

[Ofiieal Gazette June 4, 1,963.]

1. A VACUUM SWITCH COMPRISING A VACUUMIZED DIELECTRIC BULB CLOSED AT ONEEND WITH A MOUNTING PLATE HAVING AN APERTURE THEREIN, A BELLOWS HAVING ACLOSED END AND AN OPEN END HERMETICALLY FIXED ON THE MOUNTING PLATEAROUND THE APERTURE, AN OPERATING LEVER PIVOTALLY AND SLIDABLE ARRANGEDIN THE MOUNTING PLATE APERTURE AND RIGIDLY CONNECTED ON THE INSIDE OFTHE BELLOWS TO THE CLOSED END THEREOF, A DIELECTRIC SHAFT EXTENSION OFTHE OPERATING LEVER RIGIDLY CONNECTED TO THE OPPOSITE SIDE OF THE CLOSEDEND OF THE BELLOWS AND IN ALIGNMENT WITH THE OPERATING LEVER, A METALROD HERMETICALLY SEALED IN THE BULB WALL IN ALIGNMENT WITH THELONGITUDINAL AXIS OF THE BULB TO FORM A TERMINAL STUD OUTSIDE AND ACENTRAL LEAD INSIDE THE BULB, A PLURALITY OF METAL RODS HERMETICALLYSEALED IN THE BULB SIDE WALL TO FORM TERMINAL LEADS ON THE OUTSIDE ANDEVENLY SPACED POLES ON THE INSIDE OF THE BULB EXTENDING TOWARD THELONGITUDINAL AXIS OF THE BULB, AND A METAL DISTRIBUTOR ROD CONSITUTINGAN EXTENSION OF THE CENTRAL LEAD INTERPOSED BETWEEN AND MOVABLE ENGAGINGTHE FREE ENDS OF THE CENTRAL LEAD AND THE DIELECTRIC SHAFT ANDSELECTIVELY ENGAGEABLE WITH THE POLES.